1. Field of the Invention
This invention relates to techniques which may be used to expand and intensify plasma formed in a working chamber for deposition of ions and atoms onto substrates and for other purposes.
2. Description of the Related Art
In the last two decades, but particularly in recent years, significant developments have taken place in the area of plasma generation.
These have been prompted by the usefulness of plasma in all aspects of semi-conductor technology and by an ever increasing number of new applications.
Some of the areas where plasma, or its separated charged particles are used, are as ion sources, in ion rockets, in nuclear physics, in heavy-ion science, in ion plating, in crystal growth also known as ion beam epitaxy, synthesis of compound materials also known as plasma polymerization, in reactive sputtering, in ion sputtered activated reactive evaporation, in surface analysis in medical applications, in surface treatment in ion-assisted thin film deposition and in lasers and in many other applications.
As an example of the art, reference may be had to the proceedings of the International Engineering Congress, ISIAT'83 and IPAT'83 Kyoto (1983) in which a plasma system is described which was used for plasma oxidation of silicon surfaces as used in VLSI production, but the present invention has many applications besides these.
Also reference may be had to the specification of U.S. Pat. No. 3,660,715 in the name of Richard F. Post assigned to the United States Energy Commission which relates to plasma generator using a stack of pulsed washers to release ionize and heat the gas. The present invention relates to improvements in plasma generators as described in our earlier patent application No. PCT/AU86/00128.